MPs tonight backed moves to let local communities decide whether to have fluoride added to their tap water.
A bid to block the fluoridation of water was defeated, on a free vote, by 284 to 181, a majority of 103.
The issue aroused strong passions in report stage debate on the Water Bill and could now lead to a court challenge from anti-fluoride campaigners.
Water companies have had the power to fluoridate supplies since 1985 but most have not done so for fear of legal action from consumers opposed to it.
Under the Bill, health authorities will be given the power to force water companies to fluoridate supplies after local consultation.
The move is backed by the British Dental Association and four former Health Secretaries: Labour’s Alan Milburn and Frank Dobson and Tories Kenneth Clarke and Lord Fowler.
In a letter, published yesterday in the Sunday Times, they wrote that adding fluoride was considered the most effective way to reduce dental disease by experts across the world.
Fluoride supporters believe the chemical helps cut tooth decay but anti-fluoride groups claim it can cause a range of problems, from tooth mottling to cancer, and have threatened to mount a legal challenge on human rights grounds.
Plaid Cymru’s Simon Thomas (Ceredigion) said he was opposed to “compulsory medication”.
He said: “I hope the declaration will be to say we don’t have the evidence, we don’t have the public support and we don’t have the confidence at this stage, in this Bill, to pass such an important public health measure.”
Labour’s James Wray Glasgow Ballieston) said there was enough fluoride in a tube of toothpaste to kill a child and accused the Government of “dishonesty” over the issue.
Water, he said, must not be used “as a panacea for mass-medicating the whole population” against their will.
Junior health minister Melanie Johnson said it came down to a balance of judgment but spoke of one study claiming 15% more children would have no tooth decay if fluoride was added to water.
She said it could prevent thousands of children being put at “unnecessary risk” of extractions under general anaesthetic, adding: “The case is clearly made for allowing local communities to decide.”